Looking for general info on how multiuser communicates

Is there a link somewhere that explains how the multiuser setup communicates between the various servers? Looking for a general overview. So far it appears that a master DB is created on the ISP Manager server called ispconfig and all other servers have a mysql db of the services they host on that server and I assume the local db talks to the ISP Manager DB. Just trying to understand before I jump in 100% and start looking around. Any threads or URL that will help explain how it communicates would be very helpfull.

There are several threads in the forum about that but I dont have them at hand. In general the slave server connects to the master database once a minute to check for updated records that are relevant for him and copies the changes to its local database and then runs the script to update its local configuration. So a slave is not affected when the master is not available as he has a local copy of its data and the master keeps a backlog of all changes for 30 days, so if a slave is down for maintrnance for a few hours or days, it will pick up all changes from master autmatically as soon as he is online again.

I need to lurk this for Forum for a bit longer to get it down pat. I came from a Helm v3 CP windows environment and it works similar to ISPconfig Multiuser and that intrigues me, expecailly since I saw the light and have moved away from Windows web hosting and doing Centos and cPanel currrently. I have a ispConfig single user setup now and it all works well so will try expanding a bit at a time and see what happens. Absorbing all of this will just take some time.